Byoungyoung Lee 이병영

Professor, Electrical & Computer Engineering
Seoul National University
Director of the CompSec Lab
byoungyoung@snu.ac.kr

CV CompSec Lab

I work on systems security — attack mitigation, vulnerability finding, and confidential computing — spanning kernels, browsers, and trusted hardware. My recent focus is AI agent security: studying realistic attacks on LLM-based agents, such as prompt and data injection, and building principled defenses against them. More on our research →

To prospective students: I'm looking for motivated students in systems or security research. If you're interested in working with me, please reach out at byoungyoung@snu.ac.kr.

Research Updates

Jul 2026
Agent Data Injection: an arbitrary click attack against web agents — Woohyuk Choi
Jul 2026
DualView: defending personal AI agents like OpenClaw against indirect prompt injection — Juhee Kim
Jun 2026
Bad Epoll: the bug missed by Mythos — Jaeyoung Chung

Research Areas

AI Agent Security

Realistic attacks on LLM-based agents — prompt and data injection — and principled defenses like DualView and Prompt Flow Integrity.

Systems & Kernel Security

Fuzzing, concurrency bugs, and exploit mitigation across OS kernels and browsers — Razzer, OZZ, PeTAL, DMGuard, TikTag.

Confidential Computing

Trusted execution and data protection for cloud and ML pipelines — DLBox, Obliviate, SGX-Shield, TEEMATE.

Recent Publications

All publications →
2026
DMGuard: Safeguarding Kernels from Page-Use-After-Free Vulnerabilities
USENIX Security 2026 J. Kim, J. Chung, D. R. Jeong, B. Lee code
GHost in the Shell: A GPU-to-Host Memory Attack and Its Mitigation
IEEE S&P 2026 S. Roh, W. Choi, J. Chung, Y. Lee, S. Song, B. Lee code
Site Isolation is Dead: How Site Isolation is Broken in Agentic Browsers and Extensions
IEEE S&P 2026 S. Lee, S. Keum, C. Lee, D. Shin, S. Hong, B. Lee, S. Son
Heap Localization: Cache Side-Channel based Linux Kernel Heap Exploit Techniques
IEEE S&P 2026 Y. Lee, S. Roh, H. Kwon, B. Lee, T. Holz
Agent Data Injection Attacks are Realistic Threats to AI Agents
arXiv 2026 W. Choi, J. Kim, T. Kang, J. Jeong, L. Xing, B. Lee code
DualView: Preventing Indirect Prompt Injection in Personal AI Agents
arXiv 2026 J. Kim, W. Choi, T. Kang, Y. Kim, B. Lee code
2025
DLBox: New Model Training Framework for Protecting Training Data
NDSS 2025 J. Hur, J. Yi, C. Myung, S. Kim, Y. Lee, B. Lee
Secure Data Analytics in Apache Spark with Fine-grained Policy Enforcement and Isolated Execution
NDSS 2025 B. Kim⭑, J. Hur⭑, A. Ahmad, B. Lee · ⭑ co-first
TikTag: Breaking ARM's Memory Tagging Extension with Speculative Execution
IEEE S&P 2025 J. Kim, J. Park, S. Roh, J. Chung, Y. Lee, T. Kim, B. Lee code
Prompt Flow Integrity to Prevent Privilege Escalation in LLM Agents
arXiv 2025 J. Kim, W. Choi, B. Lee code
Finding Device Driver Bugs With Fuzzing PCIe Configuration Input
IEEE Access 2025 K. Boo, B. Lee
2024
PeTAL: Ensuring Access Control Integrity against Data-only Attacks on Linux
CCS 2024 J. Kim, J. Park, Y. Lee, C. Song, T. Kim, B. Lee code
OZZ: Identifying Kernel Out-of-Order Concurrency Bugs with In-Vivo Memory Access Reordering
SOSP 2024 ★ Best Paper Award D. R. Jeong, Y. Choi, B. Lee, I. Shin, Y. Kwon
Bypassing ARM's Memory Tagging Extension with a Side-Channel Attack
BlackHat USA 2024 J. Kim, J. Park, S. Roh, J. Chung, Y. Lee, T. Kim, B. Lee
A Secure, Fast, and Resource-Efficient Serverless Platform with Function REWIND
ATC 2024 J. Song, B. Kim, M. Kwak, B. Lee, E. Seo, J. Jeong
SyzRisk: A Change-Pattern-Based Continuous Kernel Regression Fuzzer
ASIACCS 2024 G. Lee, D. Xu, S. Salimi, B. Lee, M. Payer
TEEMATE: Fast and Efficient Confidential Container using Shared Enclave
arXiv 2024 C. Lee, J. Hur, S. Lee, B. Lee

All publications →

Honors & Awards

2024SOSP 2024 Best Paper Award
2023ACM CCS Top Reviewer Award
2020Ministerial citation for excellent researcher, Minister of Science and ICT (대한민국 과학기술부 장관 우수연구자 표창)
2019Google ASPIRE Award ($30,000 award)
2015Internet Defense Prize by Facebook and USENIX ($100,000 award)
2015Qualified for DARPA Cyber Grand Challenge (Team Disekt, $750,000 award)
2015Third place award by CSAW Best Applied Research Paper Award
2011The 8th place at DEFCON 19 CTF (Team PLUS@POSTECH), Las Vegas, USA
2009The 3rd place at DEFCON 17 CTF (Team PLUS@POSTECH), Las Vegas, USA
2007'Supereme Award' at Wowhacker Hacking Festival, Seoul, Korea
2006The 6th place at DEFCON 14 CTF (Team TheEastSea), Las Vegas, USA
2006'Special Prize' at KISA Hacking Defense Competition, Seoul, Korea
2005POSTECH Undergraduate Research Program Scholarship
2003Full undergraduate study scholarship, Korea Science and Engineering Foundation (KOSEF)

People

Current Students

PhD Students

MS Students

Alumni — PhD
Yuseok JeonPhD at Purdue
Co-advised with Mathias Payer. Interned at Intel. Now Assistant Professor at Korea University.
Adil AhmadPhD at Purdue
Co-advised with Pedro Fonseca. Interned at NEC and Microsoft Research. Now Assistant Professor at Arizona State University (Sep 2022).
Gwangmu LeePhD, Feb 2022
Now at Swiss National Computer Centre (CSCS).
Kyungtae KimPhD at Purdue, Aug 2022
Co-advised with Dave Tian. Now Assistant Professor at Dartmouth.
Jaewon HurPhD, Aug 2023
Now at Apple.
Cheolwoo MyeongPhD, Feb 2025
Now at Samsung Electronics.
Suhwan SongPhD, Aug 2025
Interned at Google. Now at Samsung Electronics.
Yoochan LeePhD, Aug 2025
Now PostDoc at MPI.
Kyungwook BooPhD, Feb 2026
Now PostDoc at SNU.
Juhee KimPhD, Feb 2026
Interned at Meta. Now PostDoc Researcher at Azure Research, Microsoft (UK).
Alumni — MS
Seonghyun ParkMS, Feb 2022
Now at Amazon.
Sunwoo KimMS, Feb 2022
Now at Samsung Research.
Jinwoo LeeMS, Aug 2022
Now at Healthhub.
Jinhan KwakMS, Feb 2023
Now at Start-up.
ByeongWook KimMS, Feb 2024
Now at SK hynix.
Hyokyung KimMS, Aug 2024
Now at National Security Research Institute (NSRI).
Youngjoo LeeMS, Feb 2025
Now at Apple.
Chulmin LeeMS, Feb 2025
Now at Medical School.
Chia-Ni LimMS, Aug 2026
Visitors
Jaeback Seo2018
PhD at KAIST. Now at Google.
Yuxuan Chen2018
Undergraduate at Purdue. Now at Facebook.
Wookhyun Han2018
PhD student at KAIST. Interned at Google. Now at Amazon.
Byunggill Joe2018
PhD student at KAIST.

Teaching

Seoul National University
Fall 2024Systems Programming
Fall 2024Data Structures
Spring 2024Software and Systems Security
Fall 2023Systems Programming
Fall 2023Data Structures
Spring 2023Software and Systems Security
Fall 2022Systems Programming
Spring 2021Software and Systems Security
Spring 2021Data Structures
Fall 2020Data Structures
Spring 2020Computer Architecture
Fall 2019Software Security
Spring 2019System Security Seminar
Fall 2018Advance Computer Security Theories and Techniques
Purdue University
Spring 2018Operating Systems (CS 50300)
Fall 2017Operating Systems (CS 50300)
Spring 2017Secure And Trusted Systems (CS 59000-STS)
Fall 2016Software Security (CS 52700)

Service

Program Committees
IEEE Symposium on Security and Privacy (SP)2024, 2025
USENIX Security2021, 2022, 2025
ACM Conference on Computer and Communications Security (CCS)2016 (Posters & Demo), 2017, 2018, 2021 (Web Chair), 2023, 2024
Network and Distributed System Security (NDSS)2020
ACM ASIACCS2018, 2021, 2022
ACM SafeThings2018
ACM FEAST2019, 2020
ACM CCSW2021
Engineering Secure Software and Systems (ESSoS)2017
WiSec2022
Fuzzing Workshop2023, 2024
WISA2017, 2018, 2019